Study And Application On Integral Equation Of Time Domain And It's Parallel Algorithm

The late-time-oscillations and need large quantity of computation are the important reasons which restrict the progress of the Time-Domain-Integral-Equation(IETD) arithmetic.In order to solve the late-time-oscillations problem and expand its application so that large scale computation problems about scattering and radiation in electromagnetic field can be analyzed using numerical methods,some key problems about theory and application of the arithmetic and its parallel implementation techniques were studied in this paper.The content of this thesis can be divided into three parts.In the first part,we studied the solution techniques of the IETD named the Explicit Marching-On-in-Time (MOT) method,which is combined with the Method Of Moment(MOM) based on the RWG triangular basis function.In the second part,we studied the solution technique of scattering and radiation problems about metallic objects,dielectric objects and the composite metallic and dielectric objects,as well as the late-time-oscillations problem. In the third part,the parallel solution techniques of IETD were studied.In the first part of this thesis,the time domain integral equations for metallic objects,dielectric objects and the composite metallic and dielectric objects are elaborated uniformly based on the surface equivalence principle and boundary conditions firstly.Then the solving procedures of various IETDs which based on the RWG triangular basis function were given.Lastly,the Explicit MOT technique was studied and a method to accelerate the iterative solution speed through adding a moving time window in the time steps was proposed.In the second part of this thesis,the cause of the late-time-oscillations problem coming into being was elaborated firstly.Then,aimed at how to solving the late-time-oscillations problem,two arithmetics which are universally used in solving this problem named Implicit MOT method and Marching-On-in-Degree(MOD) method which using the Laguerre polynomial as the temporal basis function were studied,and these two arithmetics were applied into solving electromagnetic characters of the metallic objects,dielectric objects and the composite metallic and dielectric objects.The results show that both the two arithmetics can eliminate the late-time-oscillations problem preferably.In the third part of this thesis,in order to solving cosmically numerical calculation by using the PCs in LAN,parallel computation technique was studied,program based on the Message-Passing-Interface(MPI) model and C++ language was established, through the analysis of the results and efficiency of parallel technique,the program were optimized and calculation efficiency were improved.And then,transplant the program onto the Super Computer Cluster of "YinHe" High Performance Compute Center, testing the efficiency of the parallel technique under 64 nodes' Linux system.Lastly,we transplant the program onto Cluster of Drwan 4000A of Shanghai Super Computer Center(SSC),and calculated the electromagnetic character of the objects with unknowns more than 60,000.